43481681 has 2 divisors, whose sum is σ = 43481682. Its totient is φ = 43481680.

The previous prime is 43481663. The next prime is 43481687. The reversal of 43481681 is 18618434.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37405456 + 6076225 = 6116^2 + 2465^2 .

It is a cyclic number.

It is not a de Polignac number, because 43481681 - 2⁶ = 43481617 is a prime.

It is a super-2 number, since 2×43481681² = 3781313165171522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (43481687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21740840 + 21740841.

It is an arithmetic number, because the mean of its divisors is an integer number (21740841).

Almost surely, 2^43481681 is an apocalyptic number.

It is an amenable number.

43481681 is a deficient number, since it is larger than the sum of its proper divisors (1).

43481681 is an equidigital number, since it uses as much as digits as its factorization.

43481681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18432, while the sum is 35.

The square root of 43481681 is about 6594.0640730888. The cubic root of 43481681 is about 351.6431068674.

The spelling of 43481681 in words is "forty-three million, four hundred eighty-one thousand, six hundred eighty-one".